Early studies by researchers at Temple University suggest that leptin levels may respond to a leptin blocker, a promising development for a new drug to add to the arsenal for treating triple-negative breast cancer. Leptin levels are elevated in 92 percent of cases of triple-negative breast cancer and help to fuel the growth of this aggressive type of breast cancer. It is a long way from studies of mice to approval for human subjects, but these early findings show that a leptin receptor blocker extended survival significantly with very few side effects.